Rodrigo Millar scored a late winner as Atlas edged Toluca 1-0 on Sunday to increase the pressure on Tigres at the top of Mexico's first division after 10 rounds of the Clausura season.
Millar struck with a fierce right-foot shot in the 81st to give Atlas the points in a tight game.
Undefeated Tigres had a 2-1 win over San Luis on Saturday and remain one point ahead of Atlas. America is in third place, four points from the top, following its 1-1 draw against Morelia on Friday.
In other weekend matches, Santos Laguna beat Atlante 2-1 with goals from U.S. striker Herculez Gomez and Oribe Peralta, Chivas beat Pachuca 1-0, Pumas snatched a 1-0 win over Puebla, Monterrey defeated Leon 2-1, Queretaro had a 1-0 win over Tijuana and Cruz Azul drew 1-1 with Jaguares.
Spain's Luis Garcia volleyed in from a corner in the 58th minute to seal Tigres' win over over San Luis.
Argentine Lucas Lobos opened the scoring in the 12th when he controlled a cross and finished with an overhead kick to give Tigres an early lead, before Yasser Corona equalized from a corner in the 25th.
Morelia held on for a point against America despite losing goalkeeper Federico Vilar in the 35th minute for a foul inside the penalty area.
Chilean Hector Mancilla's header in the opening minute put Morelia ahead but Christian Benitez equalized after half an hour.
America had a chance to go ahead before half time when Vilar was sent off, but Paraguayan Osvaldo Martinez hit the crossbar with his penalty attempt.
Chivas improved to No. 8 in the standings with a victory after Rafael Marquez Lugo hit a first-time shot from the edge of the penalty area in the 19th minute against Pachuca.
Pumas picked up a victory when Martin Bravo scored one minute from fulltime.
Jesus Zavala scored twice to give Monterrey the win against Leon, opening in 20th minute and clinching the win with a header from a freekick in the 80th.
Queretaro's Wilberto Cosme scored in the 34th to give the relegation threatened Queretaro three vital points against champion Tijuana.
Jaguares got a last-minute equalizer via an own-goal from Cruz Azul goalkeeper Jesus Corona.
